Question

Each muscle fiber contains tiny threads called _____, which are made of myosin and actin. A. ligaments B. myofibrils C. myoactin D. ATP

Answer 1

Option B, myofibrils

Step-by-step explanation:

Myofibrils are parallel filament that constitute a muscle. It has repeating sub unit called as sacromere which helps in contraction. There are two types of filament in myofibrils - thin and thick filament.

a)Thin Filament- They are made up of strands of actin protein

b) Thick Filament- They are made up of strands of myosin protein

The partially overlapping layer of thin and thick filament constitute the scaromere.

Hence, option B is correct.

Answer 2

Each muscle fiber contains tiny threads called myofibrils. The correct option among all the options that are given in the question is the second option or option "B". The other options in the question are incorrect and can be avoided. I hope the that the answer has come to your help.